Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual classe de locomotiva teve 5 itens fabricados?
 ###Tabelas: CREATE TABLE bislett_games (bislett_games_id AUTO_INCREMENT PRIMARY KEY, Year INT, Event VARCHAR, Record VARCHAR, Athlete VARCHAR, Nationality VARCHAR) CREATE TABLE singles:_21_17_titles_4_runner-ups (singles:_21_17_titles_4_runner-ups_id AUTO_INCREMENT PRIMARY KEY, Outcome VARCHAR, Year INT, Championship VARCHAR, Surface VARCHAR, Opponent VARCHAR, Score VARCHAR) CREATE TABLE west_donegal_railway (west_donegal_railway_id AUTO_INCREMENT PRIMARY KEY, Class VARCHAR, Type VARCHAR, Fleet numbers VARCHAR, Quantity made INT, Manufacturer VARCHAR, Date made INT, Date withdrawn VARCHAR) CREATE TABLE 2001_squad_statistics (2001_squad_statistics_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, Position VARCHAR, Tries INT, Goals INT, Points INT) CREATE TABLE winners_of_the_barbaro_stakes_since_1993 (winners_of_the_barbaro_stakes_since_1993_id AUTO_INCREMENT PRIMARY KEY, Year VARCHAR, Winner VARCHAR, Jockey VARCHAR, Trainer VARCHAR, Owner VARCHAR, Distance VARCHAR, Time VARCHAR, Purse VARCHAR)  
SELECT Class FROM west_donegal_railway WHERE Quantity made = 5